function comment(){
	var commentdown = document.querySelector(".commentdown");
	var comment_pulldown = document.querySelector(".comment_pulldown");
	var isBlock = false;
				//2.添加事件（点击，鼠标）
				commentdown.addEventListener("click", function() {
					if(!isBlock) {
				//3.控制样式
						comment_pulldown.style.display = "block"
						
						isBlock = true;
					} else {
						comment_pulldown.style.display = "none"

						
						isBlock = false;
					}
				})
			
			
			

}
comment();
	

